Surge absorbing chamber



2 SHEETS-SHEET 1 'G. G. HEBARD SURGE ABSORBING CHAMBER Sept. 2, 1952Filed June 13, 1947 INVENTOR.

' G.G.HEBARD BY fifl/MW ATTORNEYS Sept. 2, 19 G. 3. HEBARD SURGEABSORBING CHAMBER 2 SHEETS SHEET 2 Filed June 15. 1947 mm QV OmINVENTOR.

G G HEBARD ATTC {NEYS Patented Sept. 2, 1952 Glen :G; .Hbai'd;Barnesvme; Oklaa; 'a'ssignor m Bhilli-ps-Petroleum Gompamn a corporationof Delaware 1 Aiipiitatitfi it, 1947; Sam 1%. 754 554 await thenxttasks; This type or operation has re uce if ib raitit}iis;

gAn object of my martian is to prev v'iew" hich'w ill,- w' hen @0111 mline;""effectively absorb liSSlVB pressure sing in entsbnorm any lowpressures tli'us protect t e-now line; for shoiiaue to variations "inpres- T I V Y provide a combinat siirabsrbin anl pipe onetime devioe. aI 7 Other objects and advantages will beappai'eiit froijira -stud of theyaoeompanying -vdisc'losure stamens,

"sure 1* -sa longitudinal tiahs'x rseerosssseo tioiial view-of a deviseembodying the preferred onstriietioii of the intention.-

Figure? is a longitudinal transverse dross-see;

tional View of a" device eriibodi iria modification of my invention.- 7

j Figure 3 is aerosss'etiotial 'iiiew takeii along tl i fl lineartistes-2 V Figure 4- is a cross soti rial view sjimilafto Fig= s andmttdyifisefiotiir "modifleation or the invention. 1 Y

-fiigu're t sews-seawater view showing: an: other modification sr theinvention; q insure 1'; tip'esformss portion on flow u e aiid hasadress-sectional area substantially equalthatof'the new; use Pipe li isprovided with fiifdrations' I ih it's walls in ase'etion thereof. Theseperforations provide communicatidi'itietween use manor-suaegg-ten r orsaid: pipe and ar v1 a t or we tilde: The? new" be arranged 1114 ow avatrs e eer e? s tar-issuer btiee or iavei ntn I is to" 2 Claims; (01.its-at) raw-S 90 apart; The combined'area of the. per, forationsmay bevaried; but in most cases should equal 'or exceed the oross' seetionalarea of pipe 62 A resilient sleeve such as rubber sleeve 8-; having aninner diameter substantially larger than the exterior diameter of theperforate portion of pipe 6; is slipped 'overpipe 6 so as to cover theper-a rotate-portion thereof and to extend beyond'eaoh end or theperforate section for a considerable space; The ratiobetween'th'e innerdiameterloij said resilient sleeve and the exterior diameter-pi theperforate portiorivof pipe 6 should be witha in the range of from 111:1:tov1;5:l thought-the sizes are not limited to this ratio; outershell q,comprises an intermediate enlarged section, 10 and subintermediate'sections Mwhich haveen'a larged inner end portions which are smoothlyexpanded and belledirom theirouter end; portions to substantially thediameter of intermediate enl'arg'ed section l!) and small ends having anin"- terior diameter substantially the same, as or slightly larger thanthe exterior of rubber sleeve 8; and outer. end sections is having an;interior diameter substantiallythe same as the-linterior. diameterof theouter ends of sub-intermediate se'otio'ns Id; The interiors of sectionsIS- are belied on" their outer ends. These sections may be securedtogether in any conventional mannerrso as to make a gas tight; smoothconnection; but as shown on Figure. 1c of.thedrawing itis preferred;tdmake the connections by welds l6. ltjs-yimportant that the interior ofouter shell 'Q be sinootlito preventtearing of or damage to rubbersleeves during surges; Before securing enisestio'ns l5 tosubi-ntermediate sections 14 slip-en flanges! H are slipped over the innerends of sec tions I5 and are slipped outwardly until they eon--\tactsquare'shoulders [8 on the ends of sections [5. Flanges I! aresupplied with bolt holes interinediate their inner and outer? 1:fibrii'll" leries. Spacer sleeves?!) have inner diameters but slight 1ylarger than the exterior diameter of pipe-,0: They also haveprogressively larger exterior diarr'ieters from inner to outerends, andtapering outwardly so that the 'small 'ends thereof arebut slightlysmaller and the large ends are substan tially. larger than the interiordiameter of rubber sleeve8: :These spacer sleeves are vslipped over pipe'filso that the small ends of said sllevs -fit within rubber sleeve 8.Rubber sleeve 8 iscausd to expand at its ends by-the conical shaped? idspacer sleeves; so thatru-bbersleeye 8 is, i expansion; held against'thebelled end ofo rite shell 9 byztapered sleeve 20. Aportion-of outerendcof each sleeve 20 is recessed so that is substantially larger ininterior diameter than the exterior diameter of pipe 6 and so that astufflng box is formed by those sections of sleeves 20 and pipe 6.Packing material such as rubber packing rings 2! is slipped over theends of pipe 6 and into the stufl'ing box formed by the recessedportions of sleeves 20. Annular rings 23, having slightly largerinterior diameters than the exterior diameter of pipe 6 and slightlysmaller exterior diameters than the interior diameter of the recessedends of sleeves 20, are slipped over pipe 6 and into the stufflng boxes.Slip-on flanges 24, being supplied with bolt holes intermediate theirinner and outer peripheries and having interior diameters slightlylarger than the exterior diameter of pipe 6 are slipped over the ends ofpipe 6 and are brought against annular rings 23 to form follower means.The bolt holes in flanges l1 and 24 are matched so that rods 25,threaded on either end, may be slipped therethrough and nuts 26 screwedthereon so as to force flanges 24 toward flanges H. In this mannerannular rings 23 are forced into the stuffing boxes thus compressingpacking rings 2| to form a gas-tight seal between pipe 6 and sleeves 20.Sleeves 20 are forced inwardly by pressure from flanges 24, rings 23 andpacking rings 2| so as to compress rubber'sleeve 8 between sections land sleeves 2B, thus'forming another gas-tight seal and making agas-tight chamber 36 between outer shell 9 and rubber sleeve 8.Communication is had between chamber 36 and the exterior of said chamberthrough conduit 3l and valve 32. Any packing material 33, preferablyrubber packing, may be placedaround annular rings 23 so as to preventthe outer surface of rings 23 from collecting dirt and corrosion thereonwhich would make it vdif-,

ficult for said rings to act as followers or compres sors in thestufling boxes. Such packing material also furnishes a broader surfaceagainst ,which flanges 24 may press to move sleeves 26.

, prefer to use an inert gas such as nitrogen or carbon dioxide.

Gases of the helium group of'the periodic table may well be used tocharge chamber 30 as also may air or natural or field gas. I furtherprefer to use oxidation inhibitors as disclosed by Wolk in U. S. Patent2,363,717, in combination with such gas charge, to substantially reducedeterioration of the rubber sleeve. Rubber sleeve 8 may be made of anyresilient or rubber-like material but it is preferred to use butylrubber which is less porous and quite resistant to the escape of gasestherethrough.

In Figure 2 pipe 6 is similar to that of Figure 1, having a similarperforate portion with perforations I therein. A resilient sleeve, suchas rubber sleeve 8, is likewise similar to that of Figure 1. Spacersleeves 40 are slipped over pipe 6 and under rubber sleeve 8 at pointsbeyond each end of the perforate portion of pipe 6 so that the ends ofrubber sleeve 8 are fitted snugly to the exterior of sleeves 40 and theintermediate'section of rubber sleeve 8 between spacer sleeves. 40 isspaced from pipe 6. Spacer sleeves 40 may be fastened to pipe 6 in anyconventional manner so as to form a gas-tight connection therebetween.As shown in Figure 2 at 4|, I prefer to weld these sleeves in place.Outer shell 42 comprises an intermediate section 43 which isconsiderably larger in inner diameter than the outer diameter of rubbersleeve 8. The

4 end sections 44 of outer shell 42 are so constructed that the innerends are substantially the same size as intermediate section 43 and theinterior diameter of the outer ends is substantially the same or veryslightly larger than the exterior diameter of rubber sleeve 8. Thisouter shell may be constructed in any convenient manner. One suitablemethod'bf construction is to utilize a large piece of pipe as theenlarged intermediate section and use, for ends, swage nipples. Thesesections may be secured together in any conventional manner so as toform smooth, gastight' connections. Once again, as shown in Figure 2, Iprefer a welded connection. Outer shell 42 is sufliciently long thatwhen it is fitted over rubber sleeve 8 the constricted ends thereof fitover sections of rubber sleeve 6, which sections cover the inner ends ofspacer sleeves 40. Slip-on flanges 41 are placed over the small ends ofsections 44 and aresecured thereto in any conventional manner,preferably by welding. Stufiing boxes are formed by attaching toflanges41 annular rings 48 which are of substantially larger inner diametersthan the outer diameter of rubber sleeve 8. Followers 50 are formed byslip-on flanges 5i and annular rings 52 which rings are attached in anyconventional manner to flanges 5|. Flanges 51 and flanges 41 arepreferably supplied with bolt holes intermediate their inner and outerperipheries. Packing material such as rubber packing rings 53 is placedin the stufling boxes and followers 5| are drawn toward flanges 47 bytightening nuts 55 on threaded rods 56. Annular rings 52 are.prei'erablymachinedso that their inner diameters are but slightly, larger than theexterior diameter Gas such as disclosed above is charged to chamber 5!through valve 58 and conduit 59.

In Figure 4 another modification of the invention is shown whereinsprings 52 are attached to pipe 6 withinrubber sleeve 8 soas to resistcompression of sleeve 8 against pipe 6 and into perforations 1.

In the operation of the surge-absorbing chamber as shown in Figures 1and 2 of the drawing the gas pre-charge Within gas chambers such as 30and 51 cause the resilient sleeve to be compressed against pipe 6 orsprings 62, so that it is slightly extended, or stretched, inwardly..As, fluid surges within the flow line and/or pipe 6 it moves throughperforations l to force the resilient sleeve outwardly into its normalposition and cause some compression of the gas pre-charge. As strongersurges occurthe resilient sleeve will be expanded outwardly, thuscausing further compression of the gas" precharge in chambers 30 and 51which will substantially absorb the shock of such surges. As the crestof asurge passes, the compressed gas will force the resilient sleeveinwardly toward pipe 6, thus adding pressure to the flow line andtending to even off said flow line pressure thereby. 7

As described above, this surge absorbing chamber is utilized as anin-line chamber. Its operation, however, is equally as satisfactory whenutilized as a T or dead-end chamber. In such usage, one end of pipe 6 iscapped or plugged while the other end communicates with a fiow line.

It is obvious that a spacer may be made in other ways than thosedescribed for spacer sleeves 20 and 40. Pipe 6 could be machined on theoutside so as to have a smaller outer diameter the length of theperforate section thus making possible the spacing between rubber sleeve8 and pipe 6. By spacing the rubber sleeve away from the perforatesection of pipe 6 and pre-charging chambers 30 or 51 so as to compressrubber sleeve 8 against pipe 6 it is obvious that less expansion will berequired of rubber sleeve 8 to absorb the surges of flow than would benecessary if the rubber sleeve were fitted coincident to the surface ofthe perforate section.

Still another modification in the construction and use of this device ispossible where it is desired to save the cost of making an extra jointin a pipe. This form of surge-absorbing chamber may be so installed asto perform its surgeabsorbing function and also form a pipe couplingbetween two anchored or rigid sections of flow line. Let us suppose thatpipe 6 of Figures 1 or 2 is actually in two sections as shown by pipe 60in Figure 5, which sections make a butt joint somewhere within thebroken section of the figures. This chamber may be installed by pryingthe two sections of pipe 60 out of line far enough to slip the chamberover one section, lining up the two sections once more and slipping thechamber partially back over the second section of pipe 60. In thisinstallation, the gap between the sections of pipe 60 will serve thesame function as holes I. It Will thus be seen that when the resilientsleeve has been compressed to make the gas-tight seal for the surgechamber the surge chamber also makes a joint for the two sections ofpipe 60.

Other modifications obviously can be made without departing from thespirit or teachings of the disclosure or from the scope of the claims.

I claim:

1. A surge absorbing chamber for a flow line comprising in combination asection of said flow line, a, portion of said section of flow line beingperforate; a resilient sleeve surrounding and extending beyond the endsof said perforate portion of said flow line and having an interiordiameter substantially greater than the exterior of the perforateportion of said flow line; means to space the ends of said resilientsleeve from said flow line; an outer shell enlarged intermediate itsends to form a chamber surrounding said resilient sleeve; means tohermetically seal said chamber surrounding said resilient sleeve, andthe space between said resilient sleeve and said flow line; means tocharge said chamber with a gas under pressure; and means to prevent thepressing of said resilient sleeve against the perforate portion of saidflow line.

2. A surge absorbing chamber for a flow line comprising in combinationat least one section of said flow line, a portion of each said sectionbeing perforate and the combined area of said perforations in said flowline being at least equal to the cross-sectional area of said fiow line;a resilient sleeve surrounding and extending beyond the ends of saidperforate portion of said fiow line, the ratio between the innerdiameter of said sleeve and the outer diameter of the Perforate portionof said flow line being within the range of from 1.1:1 to 1.5:1; meansto space said resilient sleeve from said perforate portion of said flowline; an imperforate outer shell smoothly belled and expanded from itsouter ends so as to form a smooth inner-surfaced chamber ,surrounclingsaid resilient sleeve and forming the sole structural circumferentialrestraining means for said resilient sleeve; means to hermetically sealsaid chamber surrounding said resilient sleeve, and the space betweensaid resilient sleeve and said flow line; spring means to prevent thepressing of said resilient sleeve against the perforate portion of saidflow line; and means to charge said chamber with a gas under pressure.

GLEN G. HEBARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,278,688 Caminz Apr. 7, 19422,290,337 Knautt July 21, 1942 2,448,118 tPellettere Aug. 31, 19482,495,693 Byrd et al Jan. 31, 1950

